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Dissertations / Theses on the topic 'Final state'
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1
Osuna, Escamilla Carlos. "tt Analysis with Taus in the Final State." Doctoral thesis, Universitat Autònoma de Barcelona, 2009. http://hdl.handle.net/10803/3422.
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El análisis que se expone en este tesis ha sido desarrollado en el contexto del experimento ATLAS, que forma parte del acelerador hadrónico de protones LHC, instalado en un tunel de 27 Km de diámetro situado en el CERN (Ginebra). ATLAS es uno de los cuatro detectores emplazados en el anillo del acelerador junto con CMS, LHCb y Alice. Ocho años después de que el acelerador electrón-positron LEP fuera desconectado, el LHC comenzará a tomar datos en noviembre del 2009, convirtiéndose en el mayor acelerador de hadrones del mundo, tanto en luminosidad como en energía de colisión (14 TeV en centro de masas). Muchas de las cuestiones que LEP dejó sin respuesta, como la existencia del bosón de Higgs o la existencia de partículas más allá del modelo estandar necesitan energías de colisión del orden del TeV y una enorme luminosidad para acumular estadística suficiente en el tiempo de vida del acelerador. Con estos requisitos se ha construido el LHC, del que se espera que dé respuesta a estas y otras preguntas fundamentales de la física durante los 10 años en los que estará tomando datos. El análisis ha demostrado que el proceso de producción de un par top-antitop que luego decae semileptónicamente con un leptón tau que decae hadrónicamente puede ser observado, con un correcto filtrado de los procesos de ruido, incluso con los primeros datos del detector ATLAS. El estudio, basado en una simulación de MonteCarlo demuestra que tres meses de funcionamiento a baja luminosidad sería suficiente para observar del orden de 200 events de señal. El único requisito es una buena comprensión de diferentes componentes del detector y algoritmos de reconstrucción, lo cual se espera realizar en los primeros meses de toma de datos.
The analysis presented in this thesis has been developed in the context of the ATLAS experiment, part of the Large Hadron Collider (LHC), installed in a 27 Km diameter underground tunel placed at CERN (Geneva). ATLAS is one among four detectors installed along the main ring of the accelerator together with CMS, LHCb and Alice. Eight years after the electron-positron accelerator (LEP) was turned off, LHC will start taking data in November 2009, becoming the largest hadron accelerator of the world in luminosity and collision energy (14 TeV in center of mass). Many of the unanswered question that remain after LEP, like the existence of a Higgs boson or the existence of beyond the Standard Model particles need energies of collision of the order of the TeV and a great luminosity in order to be able to accumulate enough statistics along the lifetime of the experiment. LHC was build to fulfill these requirements, from which we expect to answer these and other fundamental questions of the physics during the next 10 years.
The analysis presented in this thesis has shown that the production process of a top antitop pair that later decays semileptonically with a tau lepton that decays hadronically can be observed, with a suitable event selection to reduce the physical background, even with the first data of the ATLAS experiment. The study is based on a MonteCarlo that shows that after three months taking data a low luminosity would be enough to observe about 200 signal events. The only requirement is a good knowledge of different components of the detector and reconstruction algorithms, what is expected to be achieved within the first months of data taking.
2
Morgan, Andrew Gordon. "Studies of final state photon radiation at LEP." Thesis, Durham University, 1994. http://etheses.dur.ac.uk/5952/.
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We consider two aspects of calculations involving the production of final state photons at LEP. The first addresses photons produced in association with hadrons. We motivate a measurement of the quark to photon fragmentation function and show how it can be used to account for isolated and non-isolated production rates. The second concerns the rare Z-decay to photons. We expose a subtle relationship between its various contributions. Following its investigation, we offer an improved method of calculation for weak processes at one loop.
3
Fielding, Andrew L. "Final state effects in neutron Compton scattering measurements." Thesis, University of Portsmouth, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310441.
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Soininen, Aleksi. "Final-state interactions in inelastic X-ray scattering." Helsinki : University of Helsinki, 2001. http://ethesis.helsinki.fi/julkaisut/mat/fysii/vk/soininen/.
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Khanal, Hari. "Experimental Deuteron Momentum Distributions with Reduced Final State Interactions." FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1536.
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Niecknig, Johanna [Verfasser]. "Final-state interactions in heavy-meson decays / Johanna Niecknig." Bonn : Universitäts- und Landesbibliothek Bonn, 2018. http://d-nb.info/1167856953/34.
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Azuah, Richard Tumanjong. "Momentum distributions and final state interactions in quantum fluids." Thesis, Keele University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261480.
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Strandberg, Bruno. "Low-energy processes with three pions in the final state." Thesis, Uppsala universitet, Kärnfysik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-175774.
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Doss, Natasha. "Calculated final state probability distributions for T₂ β-decay measurements." Thesis, University College London (University of London), 2007. http://discovery.ucl.ac.uk/1445423/.
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The question of a possible finite neutrino mass is one of the most investigated and controversial topics in particle physics and cosmology. The most promising direct ex periments for determining the neutrino mass are based on the study of the /-decay of molecular tritium. The mass of the neutrino is deduced by analysing the shape of the continuous energy spectrum of the electrons emitted in the /3-decay. In this thesis, the molecular physics issues facing these experiments are investigated. Theoretical final state probability distributions of the daughter molecule are calculated to satisfy the higher resolution requirements and increased sensitivity of the future ex periments. Transition probabilities to the six lowest electronically bound states of 3HeT+ are calculated. Rotational excitation of the daughter molecule is considered and probabilities obtained for the /-decay of T2 in the first four rotational states. Isotope contamination from DT and HT molecules is also investigated, and the probability distributions for 3HeD+ and 3HeH+ are calculated. The sensitivity of the initial temperature, ortho:para ratio and isotopic composition of the source is considered. Estimates of the error in the value of the neutrino mass deduced from fitting theoretical spectra, due to uncertainties in temperature, ortho:para ratio of T2 and percentage of DT molecules, are obtained. The R-matrix method is used to treat the electronic continuum of 3HeT+. Reso nances converging to the first eight excited target states are obtained, and the transition probabilities to these resonances and background continuum are calculated. Endpoint effects due to the decay of other possible species in the source - T_, T, T+, T2", Tg and T - are also investigated. It is hoped that this data will be used as part of the forthcoming KATRIN experi ment.
10
Bearden, Maria Elizabeth. "An investigation of the standardized multiple-choice departmental Calculus I final examination." Diss., Mississippi State : Mississippi State University, 2003. http://library.msstate.edu/etd/show.asp?etd=etd-11112003-080709.
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Pearson, Matthew Richard. "Final state interactions in WâºWâ» production at the ALEPH experiment." Thesis, Lancaster University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418856.
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Al-Jaghoub, Mahmoud Ismail. "Decay and final-state interaction effects of near-threshold #omega# production." Thesis, University College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362385.
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Alam, Muhammad. "Search for supersymmetry with the dilepton final state at the ATLAS experiment." Thesis, Royal Holloway, University of London, 2012. http://repository.royalholloway.ac.uk/items/f6c00f81-7bba-8c8f-42eb-ef47d83f885b/10/.
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Vaheid, Halimeh. "Generation and Validation of di-Higgs events in the 4τ final state." Thesis, Uppsala universitet, Högenergifysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-355744.
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The Higgs self-coupling has a vital role by giving a deeper understanding of the Higgs particle. Furthermore, the way it opens to physics beyond the SM, encourages us to do MC simulationstudies for varying λ_hhh . In this project, we investigate the effects of choosing different values for λ_hhh on the kinematics of all particles involved in the hh → τ τ τ τ decay channel and the resultsare compared with what we get from the SM prediction of λ_hhh .The data show that λ_hhh more close to the SM trilinear Higgs self-coupling results in generatingthe Higgs particles with the higher masses and higher momenta. On the other hand, for the moremassive Higgs bosons we have more energetic neutrinos in the final states which escape from thedetector without being detected.
15
Jackson, Shannon Marie. "FINAL Microstructure-Property Study of Cu1-xTax Thin Films." NCSU, 2007. http://www.lib.ncsu.edu/theses/available/etd-01032007-194157/unrestricted/etd.pdf.
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Morales, Tolentino Zang Daniela [Verfasser]. "Final state interactions in strong two-body baryon decays / Daniela Morales Tolentino Zang." Bonn : Universitäts- und Landesbibliothek Bonn, 2014. http://d-nb.info/1077288883/34.
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Lane, Rebecca. "Searches for neutral Higgs bosons in the tau tau final state at CMS." Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/25277.
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The Compact Muon Solenoid (CMS) detector is located at the CERN Large Hadron Collider. It is a general purpose detector designed to test predictions of the standard model (SM) and search for the Higgs boson, as well as to look for signatures of new physics beyond the SM. The analyses described in this thesis use proton-proton collision data recorded by CMS during 2011 and 2012. Searches for neutral Higgs bosons decaying into tau pairs are presented. The searches are performed separately for the SM Higgs boson or the neutral Higgs bosons of the minimal supersymmetric standard model (MSSM). The MSSM searches consist of two different analyses. The first is a direct search for any one of the MSSM neutral Higgs bosons in the mass range from 90 GeV to 1 TeV decaying directly into taus. The second searches for the signature from a heavy neutral Higgs boson of the MSSM decaying into two light MSSM Higgs bosons with SM-like properties (H → hh) in the final state with two b-quarks and two taus. The SM and MSSM ττ analyses use 4.9 fb−1 of data collected at 7 TeV and 19.7 fb−1 collected at 8 TeV, while the MSSM H → hh analysis uses only the 8 TeV data. In the SM analysis, an excess of events in data above the background expectation is observed with an observed (expected) local significance of 3.2 (3.7) standard deviations at 125 GeV. This excess is found to be consistent with the 125GeV Higgs boson of the SM in mass and coupling strengths. No significant excess is observed in either MSSM search, and so upper limits are set on cross-section times branching ratio for the Higgs production processes at the 95% confidence level. Limits are also set in mA-tanβ parameter space of several interesting MSSM benchmark scenarios.
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Soto, Ontoso Alba [Verfasser], Hannah [Gutachter] Petersen, and Albacete Javier [Gutachter] Lopez. "Initial state structures and final state correlations in heavy ion collisions / Alba Soto Ontoso ; Gutachter: Hannah Petersen, Javier Lopez Albacete." Frankfurt am Main : Universitätsbibliothek Johann Christian Senckenberg, 2018. http://d-nb.info/1169211283/34.
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Healy, James Laguna Pablo. "The final state from generic binary black hole coalescence mass, spin, and gravitational recoil /." [University Park, Pa.] : Pennsylvania State University, 2009. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-4664/index.html.
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Ruschmeier, Daniel. "Search for new physics in electron positron interactions with photons in the final state." Doctoral thesis, [S.l. : s.n.], 1999. http://deposit.ddb.de/cgi-bin/dokserv?idn=958731357.
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Ruiz, Vargas José Cupertino [UNESP]. "Search for new resonances in the merged jet plus dilepton final state in CMS." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/150892.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Na Organização Europeia para a Pesquisa Nuclear (CERN), o Large Hadron Collider (LHC) colide grupos de prótons 40 milhões de vezes por segundo a uma energia de 13 TeV. Operando junto ao LHC, o Compact Muon Solenoid (CMS) é um detector projetado para identificar uma ampla gama de partículas produzidas nessas colisões. As partículas produzidas em cada colisão são observadas nos subdetectores na busca de pistas sobre a Natureza no seu nível mais fundamental. Apesar do modelo padrão das partículas elementares ter sido testado em uma variedade de experimentos de altas energias, um dos principais objetivos do LHC é a busca de uma nova física além daquela prevista pela teoria existente. Nesse trabalho analisamos os dados de colisões próton-próton produzidos pelo LHC operando com energia de centro de massa de 13 TeV e coletados pelo CMS em 2015. O presente estudo envolve a busca de uma ressonância X não observada previamente, decaindo em um par de bósons vetoriais. Os resultados são interpretados no contexto do modelo de dimensões extras deformadas de Randall-Sundrum, distinguindo as hipóteses de fundo (modelo padrão) e fundo mais sinal (modelo padrão + graviton). Nenhuma evidência da existência de uma partícula com as características do graviton de Randall-Sundrum foi encontrada.
At the European Organization for Nuclear Research (CERN), the Large Hadron Collider (LHC) smashes groups of protons 40 million times per second at an energy of 13 TeV. Operating at the LHC, the Compact Muon Solenoid (CMS) is a multipurpose detector conceived to identify a large variety of particles produced in such collisions. The produced particles are observed at the sub-detectors in search of clues about Nature at the most fundamental level. In spite of the impressive agreement of the standard model with all the experimental results obtained so far, one of the main aims of the LHC is the search of new physics beyond the one foreseen by this theoretical model. In this work, we analyze proton–proton collisions delivered by the LHC operating at centre-of-mass energy of 13 TeV and collected by CMS during 2015. The channel under study involves the search for an unknown resonance X decaying into a pair of vector bosons. The results are interpreted in the context of the Randall-Sundrum warped extra-dimensional model, distinguishing between the hypotheses of background only (standard model) and background plus signal (standard model + graviton). No evidence of the existence of a graviton-like particle was found.
FAPESP: 2012/24593-8
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Ruiz, Vargas José Cupertino. "Search for new resonances in the merged jet plus dilepton final state in CMS /." São Paulo, 2017. http://hdl.handle.net/11449/150892.
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Orientador: Sérgio Ferraz NovaesCoorientador: Thiago R. F. P. Tomei
Banca: Alexandre Alves
Banca: Antonio Vilela Pereira
Banca: Gilvan Augusto Alves
Banca: Murilo Santana Rangel
Resumo: Na Organização Europeia para a Pesquisa Nuclear (CERN), o Large Hadron Collider (LHC) colide grupos de prótons 40 milhões de vezes por segundo a uma energia de 13 TeV. Operando junto ao LHC, o Compact Muon Solenoid (CMS) é um detector projetado para identificar uma ampla gama de partículas produzidas nessas colisões. As partículas produzidas em cada colisão são observadas nos subdetectores na busca de pistas sobre a Natureza no seu nível mais fundamental. Apesar do modelo padrão das partículas elementares ter sido testado em uma variedade de experimentos de altas energias, um dos principais objetivos do LHC é a busca de uma nova física além daquela prevista pela teoria existente. Nesse trabalho analisamos os dados de colisões próton-próton produzidos pelo LHC operando com energia de centro de massa de 13 TeV e coletados pelo CMS em 2015. O presente estudo envolve a busca de uma ressonância X não observada previamente, decaindo em um par de bósons vetoriais. Os resultados são interpretados no contexto do modelo de dimensões extras deformadas de Randall-Sundrum, distinguindo as hipóteses de fundo (modelo padrão) e fundo mais sinal (modelo padrão + graviton). Nenhuma evidência da existência de uma partícula com as características do graviton de Randall-Sundrum foi encontrada. Limites superiores com nível de confiança de 95% são estabelecidos para a seção de choque de produção da ressonância X decaindo em um par de bosons Z, para valores de massa MX no intervalo 800 - 3000 GeV. A exclusão esperada (observada) no valor de massa MX = 800 GeV é 154 fb (93 fb); para o valor de massa MX = 3000 GeV o valor de exclusão esperado (observado) diminui para 19 fb (15 fb). Um excesso com significância global igual a 2s é observado no ponto de massa MX = 1000 GeV.
Abstract: At the European Organization for Nuclear Research (CERN), the Large Hadron Collider (LHC) smashes groups of protons 40 million times per second at an energy of 13 TeV. Operating at the LHC, the Compact Muon Solenoid (CMS) is a multipurpose detector conceived to identify a large variety of particles produced in such collisions. The produced particles are observed at the sub-detectors in search of clues about Nature at the most fundamental level. In spite of the impressive agreement of the standard model with all the experimental results obtained so far, one of the main aims of the LHC is the search of new physics beyond the one foreseen by this theoretical model. In this work, we analyze proton-proton collisions delivered by the LHC operating at centre-of-mass energy of 13 TeV and collected by CMS during 2015. The channel under study involves the search for an unknown resonance X decaying into a pair of vector bosons. The results are interpreted in the context of the Randall-Sundrum warped extra-dimensional model, distinguishing between the hypotheses of background only (standard model) and background plus signal (standard model + graviton). No evidence of the existence of a graviton-like particle was found. Upper limits at 95% confidence level are set for the production cross section of a resonance X decaying to a pair of Z bosons, for values of mass MX in the range between 800 - 3000 GeV. The limit expected (observed) at MX = 800 GeV is 154 fb (93 fb); for the mass point MX = 3000 GeV the limit expected (observed) decreases to 19 fb (15 fb). A localised excess with global significance equal to 2s is observed in the mass point MX = 1000 GeV.
Doutor
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Liu, Bingxuan. "Search for displaced leptons in the e-mu final state at the CMS experiment." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1476805042657329.
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Yilmaz, Umit Oktay. "The Polarization Properties Of The Final State Particles In The Rare Radiative B-meson Decay." Phd thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606100/index.pdf.
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A general analysis of the photon and lepton polarizations in the rare Bs →
&
#61543
l+l- decay by using the most general model independent form of the effective Hamiltonian is presented. The total and the differential branching ratios for these decays, when photon is in the positive and negative helicity states, are studied. The sensitivity of "
photon polarization asymmetry"
and the longitudinal, transverse and normal polarization asymmetries of final state leptons, as well as lepton-antilepton combined asymmetries in Bs &
#8594
&
#61543
l+l- decay to the new Wilson coefficients are also investigated. It is shown that all these physical observables are very sensitive to the existence of new physics beyond SM and their experimental measurements can give valuable information about it.
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Edmonds, Keith Morgan [Verfasser]. "Supersymmetry searches in the single lepton final state with the ATLAS detector / Keith Morgan Edmonds." Mainz : Universitätsbibliothek Mainz, 2012. http://d-nb.info/1019194596/34.
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Matthaey, H. [Verfasser]. "Proton-Proton final state interaction in der Reaktion d+p→p+p+n / H. Matthaey." Karlsruhe : KIT-Bibliothek, 2009. http://d-nb.info/1186904976/34.
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Blankenship, Thomas Keith. "Rapidity gap in the final state hadron distribution in deep inelastic electron scattering at HERA." Diss., This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-06062008-170753/.
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Yap, Yee chinn. "Search for new physics with two photons in the final state with the ATLAS detector." Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCC005/document.
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Le sujet de cette thèse est la recherche de signaux de physique au-delà du modèle standard,dans le canal de désintégration en deux photons, dans les collisions proton-proton enregistrées par le détecteur ATLAS à des énergies dans le centre de masse de √s = 8 TeV en 2012 et√s = 13 TeV en 2015 et 2016.Une étude de faisabilité de la recherche d’un boson pseudo-scalaire A se désintégrant en un boson Z et un boson de Higgs d’une masse de 125 GeV est présentée. Cette étude est effectuée dans le contexte de modèles prédisant deux doublets de Higgs. L’état final recherché est constitué de deux jets hadroniques et deux photons et les données utilisées sont celles enregistrées en 2012 `a √s = 8 TeV, correspondant `a une luminosité intégrée de 20.3 fb−1. La sensibilité attendue est comparable `a celle atteinte avec une autre recherche effectuée dans la collaboration ATLAS, basée sur l’état final constitué d’une paire d’électrons ou muons et d’une paire de leptons τ . En revanche, elle est inférieure à celle des études dans lesquelles le Higgs est recherché dans sa désintégration en une paire de quarks beaux.La recherche de nouvelles résonances de haute masse se désintégrant en deux photons dans les collisions `a 13 TeV est également présentée. Les échantillons analysés correspondent à des luminosités intégrées de 3.2 fb−1 en 2015 et 12.2 fb−1 en 2016. Deux études sont développées :l’une est optimisée pour la recherche, aussi générale que possible, d’une particule de spin 0; la seconde cible une particule de spin 2 telle que le graviton prédit par le modèle de Randall-Sundrum. Une attention particulière est portée `a la compréhension et la paramétrisation de la forme de la résonance dans l’hypothèse où celle-ci aurait une largeur naturelle non négligeable.L’analyse des données enregistrées en 2015 conclut `a l’observation d’un léger excès autour d’une masse de 750 GeV, d’une largeur d’environ 45 GeV, et dont la significativité statistique locale est estimée à 3,9 et 3,8 écarts standard selon le spin de la résonance recherchée. La significativité globale est estimée à 2,1 écarts standard. L’analyse des données enregistrées en 2016 ne mène à l’observation d’aucun excès significatif. Des limites sur le produit de la section efficace de production d’une résonance par le taux de désintégration en deux photons sont établies : pour une résonance de spin nul, elles vont de 12 fb (51 fb) `a une masse de 200 GeV `a 0,2 fb (0,3 fb)`a 2400 GeV, dans l’hypothèse d’une largeur naturelle de 4 MeV (10% de la masse). Une étude de la reconnaissance des photons se convertissant en une paire électron-positon avant d’interagir avec les calorimètres, basée sur la forme de la gerbe électromagnétique détectée est également documentée. Cette étude a deux objectifs : d’une part, améliorer l’identification des photons convertis dans le contexte de taux d’empilement élevés ; d’autre part, fournir une méthode d’identification basée sur des informations indépendantes (calorimétriques) de celles utilisées par la méthode standard (trajectoires des particules chargées) afin d’évaluer les performances de cette dernièreThis thesis reports on the search for new physics in the diphoton decay channel with the protonprotoncollision data collected by ATLAS at a centre-of-mass energy of √s = 8 TeV in 2012and √s = 13 TeV in 2015 and 2016.A feasibility study of the search for a pseudoscalar A decaying to a Z boson and a 125 GeVHiggs boson in the context of an extended Higgs sector, namedly the two-Higgs-doublet models,is presented. The search is performed with a final state of two jets and two photons using20.3 fb−1 of data at √s = 8 TeV. The expected sensitivity is found to be competitive with theanalysis with a final state of two electrons or muons and two τ leptons, but less sensitive to theother searches with the Higgs decaying to a pair of b-quarks.Search for high mass resonances decaying to two photons at √s = 13 TeV is also presented.The analysed dataset corresponds to an integrated luminosity of 3.2 fb−1 in 2015 and 12.2 fb−1in 2016. Two searches are performed: one optimised for a generic spin-0 particle, and theother for a spin-2 particle using Randall-Sundrum graviton model as benchmark. Particularattention is paid to the understanding and the parameterisation of the line shape of a largewidthresonance. In the search using the collision data recorded in 2015, a moderate excess wasobserved at a diphoton invariant mass around 750 GeV with a best-fit width of around 45 GeV,corresponding to a local significances of 3.8-3.9 standard deviations, depending on the spin ofthe resonance being searched for. The global significances are estimated to be 2.1 standarddeviations. The search is updated with 2016 data and no significant excess is observed. Limitson the production cross-section times branching ratio to two photons for the two resonancetypes are reported: for a spin-0 resonance, the fiducial cross-section ranges from 12 fb (51 fb) at200 GeV to 0.2 fb (0.3 fb) at 2400 GeV, with the narrow (10% of the mass) width hypothesis.A part of this document is also devoted to the study of photons that convert into electronpositronpairs before entering the calorimeter using their electromagnetic shower information.The conversion study has two objectives: improving the identification of photon conversion athigh pile-up rate and providing an orthogonal classification method to assess the performanceof the standard track-based algorithm
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Grohsjean, Alexander. "Measurement of the Top Quark Mass in the Dilepton Final State using the Matrix Element Method." Diss., lmu, 2009. http://nbn-resolving.de/urn:nbn:de:bvb:19-100745.
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Hay, Genevieve. "f¦o(1370) resonance contribution to final state interactions in the reaction ãã --> [pi pi]." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0021/MQ36930.pdf.
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Norman, Matthew. "Search for non-standard model signatures in the WZ/ZZ final state at CDF Run II." Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p3355835.
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Thesis (Ph. D.)--University of California, San Diego, 2009.Title from first page of PDF file (viewed July 2, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 149-150).
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Falla, R. J. "Search for Higgs boson pair production in the bƃbƃ final state at the Large Hadron Collider." Thesis, University College London (University of London), 2016. http://discovery.ucl.ac.uk/1482160/.
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The work presented in this thesis focuses on the search for resonant and non-resonant Higgs boson pair production in the bƃbƃ final state at the LHC. All of the searches require the use of high transverse momentum b-tagged jet systems. The first search presented is performed using a dataset of proton- proton collisions at √s = 8 TeV, collected in 2012 with the ATLAS detector, corresponding to an integrated luminosity of 19.5 fb^{-1}. The Higgs boson decay products are reconstructed as a pair of close- by small radius b-tagged jets with a high transverse momentum, known as "dijets". The resonant signals looked for are a Randall- Sundrum Kaluza-Klein graviton, G^*, and a heavy neutral scalar boson in the 2HDM model, H. A non-resonant search is also performed. No evidence for resonant or non-resonant Higgs boson pair production is observed. An upper limit on the cross-section for σ(pp → G^* →hh→bƃbƃ) of 3.2 fb is set for a G^* mass of 1.0 TeV, at the 95% confidence level. The search for non-resonant Standard Model hh production sets an observed 95% confidence level upper limit on the production cross-section σ(pp → hh → bƃbƃ) of 202 fb, compared to a SM prediction of σ(pp → hh → bƃbƃ) = 3.6 ± 0.5 fb. In preparation for Run 2 and the HL-LHC simulation studies based on √s = 14 TeV are made. A non-resonant search using the dijet method used in Run 1 is presented. A resonant study is also presented which shows a new method for reconstructing pp → X →hh→bƃbƃ events. It uses the combination of many Higgs boson reconstruction techniques which vary with the Higgs boson transverse momentum and is shown to be excellent at providing a high signal efficiency.
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Wehrmeyer, Lara. "Influence of Active Musculature & Parameters of the Final Pre-Crash State on the Occupant Response." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-277117.
Full textAbstract:
Collision avoidance systems have become an integrated part of modern vehicles and aim to avoid accidents or mitigate the crash severity for the occupant. For example, the autonomous emergency braking system influences the pre-crash state of the occupant in sitting posture, stress state, or velocity. The occupant might try to retain its posture by activating muscles, which induce muscle bracing and could counteract the movement of the occupant in the pre-crash phase. Therefore, it is essential to study the influence of active musculature on occupant response in pre-crash and crash events. A finite element human body model (HBM) with and without closed-loop muscle activation control was used to simulate the occupant response during those events. Comparing the HBM responses & head kinematics reveal an influence of muscle bracing in the evasive braking manoeuvre. Simulating the pre-crash and in-crash phase in two stages can provide multiple benefits. However, the correlation between a single-stage simulation (baseline) and a two-stage simulation needs to be investigated. The baseline simulation uses an active HBM to model an occupant during an evasive braking manoeuvre and the muscles are deactivated when entering the frontal impact phase. The parameters of the final pre-crash state, which are needed to mimic the baseline’s response when transitioning from the pre-crash to the in-crash event are investigated in this study. For that reason, sitting position, stress state and velocity are transferred respectively to the initial passive in-crash HBM state. The simulations enabled the comparison of occupant response and calculation of cross-correlation. Each retainment strategy gave a good cross-correlation with the baseline simulation.Kollisionsundvikande system har blivit en viktig del i moderna fordon där syftet är att undvika olyckor samt att minska allvarhetsgraden av olyckor för de åkande. Ett exempel är nödbromssystem som kan påverka den åkandes initiala tillstånd direkt före en krock som, till exempel, sittposition, spänningstillstånd, eller initial hastighet inför krock. Den åkande kan försöka att bibehålla sin hållning genom att aktivera sina muskler vilket påverkar rörelsen av dess kropp under för-krocks fasen. Det är därför viktigt att studera hur aktiva muskler påverkar rörelsen av kroppen hos den åkande under både före krocksfasen och själva krockfasen. En finit element humanmodell (HBM) med och utan reglerad muskelaktivitet används för att prediktera responsen hos den åkande i båda faserna. En jämförelse mellan simuleringarna visar att aktiva muskler kan påverka åkandekinematiken under bromsningsförloppet. Att simulera fasen före krock och fasen under krock i två steg kan medföra flera fördelar. Korrelationen mellan en enkelstegssimulering (originalsimulering) och en tvåstegssimulering måste dock studeras. Som originalsimulering används en aktiv HBM för att modellera den åkande under för-krocksfasen där den reglerade muskelaktiviteten inaktiveras under krockfasen. I denna studie undersöks den åkandes initiala tillstånd före krocken som behövs för att efterlikna originalsimulerings respons vid övergången från för-krocksfasen till krockfasen. Av den anledningen mappas det passiva HBM-tillståndet till det slutliga tillståndet av före krocksfasen för sittposition, spänningstillstånd respektive hastighet. Simuleringarna möjliggjorde en jämförelse av åkande respons och beräkning av korskorrelation. Varje mappningsstrategi gav en bra korskorrelation med originalsimuleringen.
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Rold, Robert E. "Underwater observations of fish attractors in a final cut coal mine lake." Virtual Press, 1987. http://liblink.bsu.edu/uhtbin/catkey/483472.
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Two types of fish attractors, brush attractors made of cedar trees and Berkley and Company's Fish-Hab modules, were placed in a final cut coal mine lake and evaluated for fish concentrating effectiveness. Dives were conducted biweekly and numbers and species of fish at attractors were recorded. Data were then evaluated using Analysis of Variance tests.A total of 623 fish were recorded on attractors during the eight dives made from July 21 to October 24, 1986. Brush attractors held 485 fish or 78% of the total. Module attractors concentrated 105 fish (17%) and 33 fish (5%) were observed in the control areas. Brush attractors concentrated nearly five times as many fish as the modules and 15 times as many fish as the control area. The modules concentrated over three times as many fish as the control area. Results indicated there was no significant difference (0.05) in numbers of fish attracted by brush and modules with an Analysis of Variance With Repeated Measures test but density of individual species was not considered. Furthur analysis of attractors by date and specie over the study period using a One-Way Analysis of Variance revealed that brush attractors concentrated significantly (0.05) more fish than modules in mid to late summer, but not in the early fall. Modules were much less effective at concentrating fish and were never significantly different than the control areas.Scuba diving worked well as a method of evaluation for the attractors. Water clarity was adequate for visual observations and fish did not display a fright response or leave when the diver approached. At no time was there difficulty in identifying or counting fish greater than 10 cm.Ball State UniversityMuncie, IN 47306
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João, Maria Thereza David. "Estado e elites locais no Egito do final do IIIº milênio a.C." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/8/8138/tde-10122015-155852/.
Full textAbstract:
Poucos estudos têm se dedicado a explorar de forma mais sistemática o processo que levou ao fim do Reino Antigo (2686 a 2160 a.C.) e ao advento do Primeiro Período Intermediário (2160-2055 a.C.) no Antigo Egito. A relativa escassez de fontes sempre foi um dos argumentos usados para rotular esse momento da história egípcia como uma idade das trevas, na qual a civilização do Nilo teria mergulhado em profundo caos decorrente do enfraquecimento da monarquia unificada articulada em torno do faraó e da elite menfita. Nesse entendimento períodos como esse, de retração da capacidade centralizadora do Estado, permanecem alijados da histórica política egípcia e são encarados como meros hiatos dentro de um curso supostamente natural de centralização política. Pretendendo rever essas interpretações, este estudo se debruça sobre a organização da administração estatal egípcia no período que cobre especialmente da Vª dinastia ao Primeiro Período Intermediário. A análise da documentação, que engloba decretos régios e autobiografias inscritas nas tumbas de alguns dos mais destacados funcionários dessa época, demonstra que a corrente percepção acerca do fim do Reino Antigo, na qual as reformas administrativas empreendidas entre a Vª e VIª dinastias teriam provocado excesso de poder das elites locais, levando-as a se autonomizar e a concorrer com o próprio Estado, é equivocada. Partindo de um concepção materialista a respeito do que se entende por Estado foi possível notar que o poder das elites provinciais, no Reino Antigo, articulava-se em torno de pelo menos três eixos principais: através do exercício de funções burocráticas na administração estatal; como responsáveis por instalações régias nas províncias, a exemplo do Hwt; e por intermédio da administração e sacerdócio tanto em templos de divindades locais quanto nas chamadas capelas do ka, destinadas ao culto dos monarcas egípcios. A conclusão é a de que a autonomia de certos grupos provinciais frente ao poder menfita se dá somente após o enfraquecimento deste último, não estabelecendo com ele uma relação causal. Tal autonomia não se configura, igualmente, como um processo de oposição ao Estado, uma vez que elites locais e Estado sei inseriam na lógica estatal por meio de laços de solidariedade e reciprocidade essenciais ao equilíbrio de ambos. Ao ofertar nova luz ao estudo da administração egípcia busca-se repensar as condições que levaram ao declínio do Reino Antigo, assim como reavaliar o lugar do Primeiro Período Intermediário na história egípcia através de uma perspectiva integradora, inserindo-o na dinâmica das relações de poder que marcaram a trajetória dessa sociedade como um momento fundamental no qual administração estatal, longe de entrar em colapso, reorganizase e se rearticula.Only a few studies have systematically explored the process that led to the ending of the Old Kingdom (2686-2160 B.C) and the arrival of the First Intermediate Period (2160-2055 B.C) in Ancient Egypt. The relative lack of sources has always been an argument to label this moment of the Egyptian history has a period of dark ages, when the Nile civilization supposedly dived into deep chaos due to the weakening of the unified monarchy that jointed around the pharaoh and the Memphite elite. To this understanding, periods like that one, in which the States centralizing capacity retracted, remain excluded from the Egyptian political history and are faced as mere hiatus in a supposedly natural course of political centralization. Aiming to revise such interpretations, the present study discusses the organization of the Egyptian State administration from the 5th dynasty to the First Intermediate Period. The analysis of documents like royal decrees and autobiographies written in the tombs of some of the more distinguished officers of the period, points out the misconception of the current comprehension about the ending of the Old Kingdom. From our point of view, the administrative reforms made between the 5th and the 6th dynasties did not necessarily provoke an excess of power among the local elites, and therefore did not necessarily lead them to become autonomous and then concur with the State. By having in mind a materialistic conception of State, we could notice that the provincial elites power during the Old Kingdom jointed around at least three main perspectives: the exercise of bureaucratic functions in the State administration; the responsibility for royal installations in the provinces, like the hwt for example; and the administration and priesthood in local divinities temples and ka chapels, destined to the cult of the Egyptian monarchs. We have concluded that certain provincial groups started to become autonomous and to face the Memphite power only after this ones hegemony started to weaken; therefore, there is no causal relation. In the same way, such autonomy did not mean an opposition to the State, since the local elites and the State were bounded by solidarity and reciprocity laces which were essential to the balance of both. By offering a new perspective to the study of the Egyptian administration, we aim to rethink the conditions that led to the fall of the Old Kingdom and reevaluate the place of the First Intermediate Period in Egyptian history. We propose an integrating perspective that puts this period into the dynamics of power relations that marked the trajectory of that society as a fundamental moment in which the State administration, far from collapsing, reorganized and rearticulated itself.
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Akin, Ilina Vasileva. "Search For Scalar And Tensor Unparticles In The Diphoton Final State In Cms Experiment At The Lhc." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12610952/index.pdf.
Full textAbstract:
We present a search for scalar and tensor unparticles in the diphoton final state produced in pp collisions at a center-of-mass energy of 10 TeV, with the CMS detector at LHC. The
analysis focuses on the data sample corresponding to the integrated luminosity of 100 pb−
1, expected to be collected in the first LHC run. The exclusion limits on unparticle parameters, scaling dimension dU and coupling constant lambda, and the discovery potential for unparticles are presented. This is the first simulation study of the sensitivity to unparticles decaying into the diphoton final state at a hadron collider.
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Lindemann, Dana. "The search for rare non-hadronic B-meson decays with final-state Neutrinos using the BaBar detector." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=110563.
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This thesis presents the searches for two rare B meson decays: the radiative leptonic decay B+ -> l+ nu gamma (l = e, mu) and the flavor-changing neutral current B -> K(*) nu nubar. These searches use the full dataset collected by the BaBar experiment, which corresponds to almost 500 million BB pairs. After fully reconstructing the hadronic decay of one of the B mesons in Upsilon(4S) -> BB decays, evidence of B+ -> l+ nu gamma or B -> K(*) nu nubar is looked for in the rest of the event. No significant evidence of either signal decay is observed. Model-independent branching-fraction upper limits are set at BR(B ->e nu gamma)<17 x10^{-6}, BR(B ->mu nu gamma)<24 x10^{-6}, and BR(B ->l nu gamma)<15.6 x10^{-6}, all at the 90% confidence level. These are currently the most stringent published upper limits for B+ -> l+ nu gamma. In addition, branching-fraction upper limits are set at BR(B -> K+ nu nubar)<3.7 x10^{-5}, BR(B -> K0 nu nubar)<8.0 x10^{-5}, BR(B -> K*+ nu nubar)<11.5 x10^{-5}, and BR(B -> K*0 nu nubar)<9.2 x10^{-5}, all at the 90% confidence level. For additional sensitivity to New Physics contributions, partial B -> K(*) nu nubar branching-fraction upper limits are also determined over the full kinematic range.Cette thèse présente l'étude de deux désintégrations rares de mésons B: la désintégration radiative leptonique B+ -> l+ nu gamma (l = e, mu) et le courant neutre qui change la saveur B -> K(*) nu nubar. Ces études utilisent l'ensemble des données recueuillies par l'expérience BaBar, ce qui correspond à près de 500 millions paires BB. Après la reconstruction totale de la désintégration hadronique de l'un des mésons B dans la désintégration Upsilon(4S) -> BB, la manifestation de B+ -> l+ nu gamma ou B -> K(*) nu nubar est recherché dans le reste de l'événement. Aucune preuve significative de la désintégration du signal n'a été observée. Les limites supérieures du rapport d'embranchement indépendantes du modèle sont évaluées à BR(B -> e nu gamma)<17 x10^{-6}, BR(B -> mu nu gamma)<24 x10^{-6}, et BR(B -> l nu gamma)<15,6 x10^{-6}, à un niveau de confiance de 90%. Ce sont actuellement les limites supérieures les plus strictes publiés pour B+ -> l+ nu gamma. De plus, les limites supérieure du rapport d'embranchement sont évaluées à BR(B -> K+ nu nubar)<3,7 x10^{-5}, BR(B -> K0 nu nubar)<8,0 x10^{-5}, BR(B -> K*+ nu nubar)<11,5 x10^{-5}, et BR(B -> K*0 nu nubar)<9,2 x10^{-5}, à un niveau de confiance de 90%. Pour demeurer réceptives aux contributions de la nouvelle physique, les limites supérieures du rapport d'embranchement partiel de B -> K(*) nu nubar sont déterminés dans le spectre cinématique complet.
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Morgenstern, Marcus Matthias. "Search for heavy resonances decaying into the fully hadronic di-tau final state with the ATLAS detector." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-139662.
Full textAbstract:
The discovery of a heavy neutral particle would be a direct hint for new physics beyond the Standard Model. In this thesis searches for new heavy neutral particles decaying into two tau leptons, which further decay into hadrons, are presented. They cover neutral Higgs bosons in the context of the minimal supersymmetric extension of the Standard Model (MSSM) as well as Z′ bosons, predicted by various theories with an extended gauge sector. Both analyses are based on the full 2012 proton-proton collision dataset taken by the ATLAS experiment at the Large Hadron Collider (LHC). The extended Higgs sector in the MSSM suggests additional heavy neutral Higgs bosons which decay into tau leptons in about 10% of the time. Given that the dominant final state, φ → b¯b, suffers from tremendous QCD initiated backgrounds, the decay into two tau leptons is the most promising final state to discover such new resonances. The fully hadronic final state is the dominant one with a branching fraction of about 42%. It governs the sensitivity, in particular at high transverse momentum when the QCD multijet background becomes small.
Other theoretical extensions of the Standard Model, which are mainly driven by the concept of gauge unification, predict additional heavy particles arising from an extended underlying gauge group. Some of them further predict an enhanced coupling to fermions of the third generation. This motivates the search for Z′ bosons in the fully hadronic di-tau final state.
One major challenge in physics analyses involving tau leptons is to have an outstanding performance of trigger and identification algorithms suitable to select real tau leptons with high efficiency, while rejecting fake taus originating from quark or gluon initiated jets. In this work a new tau trigger concept based on multivariate classifiers has been developed and became the default tau trigger algorithm in 2012 data-taking. An updated tau identification technique based on the log-likelihood approach has been provided for 2011 data-taking. Furthermore, a new framework has been developed to perform the tuning of the tau identification algorithm and exploited for the optimisation for 2012 data-taking, accordingly.
The search for new heavy neutral Higgs bosons in the context of the MSSM has been performed exploiting the full 2012 dataset corresponding to an integrated luminosity of 19.5 fb−1 taken at a centre-of-mass energy of √s = 8 TeV. Updated event selection criteria and novel data-driven background estimation techniques have been developed and are suitable to increase the sensitivity of the analysis significantly. No deviations from the Standard Model prediction are observed, and thus 95% C.L. exclusion limits on the production cross section times branching ratio, σ(pp → φ) × BR(φ → ττ), are derived exploiting the CLs method. The exclusion ranges from 13.0 pb at 150GeV to 7.0 fb at 1 TeV for Higgs boson production in association with b-quarks and from 23.6 pb at 150GeV to 7.5 fb at 1 TeV for Higgs bosons produced via gluon-gluon fusion. The obtained exclusion limit on σ(pp → φ) × BR(φ → ττ) can be related to an exclusion of the MSSM parameter space in the MA-tan β-plane. Various benchmark scenario are considered. The ”standard candle” is the mhmax scenario, for which tan β values between 13.3 and 55 can be excluded at 95% C.L. in the considered mass range. Updated benchmark scenarios designed to incorporate the recently discovered SM-like Higgs boson were suggested and analysed as well. In the mhmod+ (mhmod−) scenario tan β values between 13.5 (13.3 ) and 55 (52 ) can be excluded.
Finally, a search for heavy neutral resonances in the context of Z′ bosons was performed. As in the search for new Higgs bosons, no deviation from the Standard Model prediction is observed, and hence exclusion limits on the production cross section times branching ratio, σ(pp → Z′) × BR(Z′ → ττ), and on the Z′ boson mass are derived exploiting the Bayesian approach. Z′ bosons with MZ′ < 1.9 TeV can be excluded at 95% credibility, and thus mark the strongest exclusion limit obtained in the di-tau final state by any collider experiment so far.
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Brown, Jonathan. "Search for WH associated production in the lνbb final state using the DØ detector at the Tevatron." Phd thesis, Université Paris-Diderot - Paris VII, 2011. http://tel.archives-ouvertes.fr/tel-00918068.
Full textAbstract:
Le Modèle Standard est le cadre qui permet de décrire les interactions entre les particules et leur dynamique. Le mécanisme de Higgs est une solution pour introduire naturellement un terme de masse dans la description théorique de ce modèle. Après la rupture spontanée de la symétrie électrofaible, une nouvelle particule scalaire massive est introduite, le boson de Higgs. Comme celui-ci n'a pas encore été découvert, la recherche du boson de Higgs est effectué au Tevatron, qui est un collisionneur pp ̄ à une énergie au centre de masse de 1.96 TeV. Pour MH = 135 GeV, le mode de désintégration dominant est H → bb ̄. L'analyse présentée dans ce document est axée sur le domaine en masse 100 < MH < 150 GeV, dans le canal où le boson de Higgs est produit en association avec un boson W se désintègrant en un lepton chargé (électron ou muon) et un neutrino. L'étude de cet état final repose sur les informations recueillies auprès de toutes les parties du détecteur DØ. Un résultat basé sur 5.3 fb−1 de collisions récoltées durant le RunII du Tevatron est présenté ici. Afin d'augmenter la sensibilité au signal, l'analyse est séparée en sous-canaux en fonction de la saveur du lepton considéré, le nombre de jets dans l'état final, le nombre de jets identifiés comme provenant de quarks b et par périodes de prise de données. Après sélection des événements, une technique d'analyse multivariée est utilisée pour séparer les événements de type signal du bruit de fond physique et instrumental attendu. Comme un bon accord entre les données et simulation est observé, une limite supérieure observée (attendue) de 4.5 (4.8) est placée (pour MH = 115 GeV) sur le rapport entre la section efficace pp ̄ → W H multipliée par le rapport d'embranchement H → bb ̄ et la prédiction du Modèle Standard, à 95% de niveau de confiance. Alors que les dernières données du Tevatron sont en cours d'analyse, les perspectives de recherche au Tevatron sont exposées ici. Les améliorations futures pour la publication finale sur la recherche dans le canal WH → lνbb ̄ sont présentées. La masse invariante dijet étant la variable la plus discriminante, l'amélioration de la résolution du pic de masse est un enjeu important, ainsi que l'optimisation de l'utilisation des outils d'identification de jets de quarks b et du discriminant final. Une amélioration significative est obtenue au niveau de la limite.
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Reinsch, Andreas, and Andreas Reinsch. "Search for Colorful Quantum Black Holes Decaying to an Electron-Jet Final State with the ATLAS Experiment." Thesis, University of Oregon, 2012. http://hdl.handle.net/1794/12370.
Full textAbstract:
A search for quantum black holes with color charge decaying to one electron and
one quark has been performed using data collected by the ATLAS Experiment at
the Large Hadron Collider corresponding to 2.29 fb−1. No excess over the expected
Standard Model interactions has been observed. Limits are set on the production
cross section for events with one electron and one jet resulting from new physical
phenomena. Models with a combined invariant mass of the electron and jet larger
than or equal to 2.5TeV and a cross section above 2.6 fb are excluded at the 95%
confidence level. This allows the exclusion of a significant part of the parameter
space of quantum black hole models.
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Pettersson, Nora. "Study of systematic effects from the level of Final State Radiation in tt-background to SUSY dilepton channels." Thesis, KTH, Partikel- och astropartikelfysik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-93450.
Full textAbstract:
Uncertainties in radiative effects of the quarks in -background in the form of final state radiation (FSR) are significant when it comes to reducing all forms of systematics that can arise from measuring the jets energy. Analysis on FSR is in general conducted on different simulated samples where one has included the radiative effect using algorithms such as PYTHIA[29]. The hypothesis is that through the re-weighting of the -background nominal sample one could add a better representation of the FSR effect. Finding a simple way to include a better description of FSR would not only save time in the simulation process but it would also be a way to reduce the systematic errors originating from limited MC statistics. Due to statistical effects coming from the simulations one cannot use the basic approach to define the effect of FSR as simply the difference between nominal and FSR. Two methods are tested to estimate the FSR effects; the first method uses a set of efficiency factors to represent the signal regions, the second method is to add a weight to the events of the nominal sample. The first method show positive results, especially in SR2, compared to a basic analysis, with an uncertainty of the FSR effect of: SR1:±29% SR2: ±51% SR3: ±37%. While a basic analysis gave an uncertainty of ±42%, ±122% and 36%. The second method shows positive signs where the re-weighted sample moves closer to the behaviour of the FSR sample. However, both methods are based on insufficient amount of statistics to draw any absolute conclusions.
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Schluefter, R. [Verfasser]. "Winkelverteilung der Neutron-Proton-Final-State-Interaction in der Reaktion d + d--->d + p + n / R. Schluefter." Karlsruhe : KIT-Bibliothek, 2010. http://d-nb.info/1188749900/34.
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Kang, Xian-Wei [Verfasser]. "Chiral Dynamics and Final State Interactions in Semileptonic B Meson Decay and Antinucleon-Nucleon Scattering / Xian-Wei Kang." Bonn : Universitäts- und Landesbibliothek Bonn, 2014. http://d-nb.info/1238687415/34.
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Schwindt, Thomas [Verfasser]. "Evidence for the Higgs Boson Decay to tau+ tau- in the Lepton + Hadrons Final State with ATLAS / Thomas Schwindt." Bonn : Universitäts- und Landesbibliothek Bonn, 2015. http://d-nb.info/1077289472/34.
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Büscher, Daniel [Verfasser], and Karl [Akademischer Betreuer] Jakobs. "Search for Higgs bosons with b-jets in the final state in proton-proton collisions with the ATLAS experiment." Freiburg : Universität, 2016. http://d-nb.info/1122831013/34.
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Keyes, Robert. "New angular search for exotic physics in the photon+jet final state using the ATLAS detector on the LHC." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=114367.
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This thesis outlines developments towards a new analysis and search technique for heavy resonances in angular distributions of photon+jet final states for the 2012 data set from the ATLAS detector on the LHC. In particular, a new angular variable tailored to the photon+jet channel was defined which distinguishes between background and expected signals, the corresponding angular observable sensitivity was optimized using ATLAS excited quark samples and JetPhox MC samples, and an optimal mass binning scheme was derived from the measured mass resolution. Ongoing work is being done to publish the analysis.La présente thèse aborde le développement d'une nouvelle analyse et technique de recherche pour des resonances massives dans les distributions angulaires des états finaux dits photon+jet parmi les données récoltées en 2012 parle détecteur ATLAS du LHC. Une nouvelle variable angulaire développée sur mesure pour le canal photon+jet a d'ailleurs été définie afin de pouvoir distinguer le bruit de fond du signal plus efficacement. La sensitivité de cette observable a été optimisée en utilisant des échantillons Monte Carlo de quarks excités ainsi que du programme JetPhox. Une classification optimale en terme de masse a aussi été dérivée à partir de la mésure de la résolution de masse. Des travaux sont en course afin de publier l'analyse.
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Primavera, Federica <1985>. "Search for the MSSM Neutral Higgs Boson in the mu+mu- final state with the CMS experiment at LHC." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6215/.
Full textAbstract:
In this thesis, my work in the Compact Muon Solenoid (CMS) experiment on the search for the neutral Minimal Supersymmetric Standard Model (MSSM) Higgs decaying into two muons is presented. The search is performed on the full data collected during the years 2011 and 2012 by CMS in proton-proton collisions at CERN Large Hadron Collider (LHC).
The MSSM is explored within the most conservative benchmark scenario, m_h^{max}, and within its modified versions, m_h^{mod +} and m_h^{mod -}.
The search is sensitive to MSSM Higgs boson production in association with a b\bar{b} quark pair and to the gluon-gluon fusion process.
In the m_h^{max} scenario, the results exclude values of tanB larger than 15 in the m_A range 115-200 GeV, and values of tanB greater than 30 in the m_A range up to 300 GeV. There are no significant differences in the results obtained within the three different scenarios considered. Comparisons with other neutral MSSM Higgs searches are shown.
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Teklishyn, Maksym. "Measurement of the η c (1S) production cross-section via the decay η c to proton-antiproton final state." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112224/document.
Full textAbstract:
Cette thèse répond une étude de la η c (1S) d'état de charmonium utilisant désintégrations à l'état final proton-antiproton à l'expérience LHCb. La section efficace de production du méson η c dans les interactions parton et dans les désintégrations b-hadrons sont signalés. La production de l'état η c (1S) est mesurée par la désintégration de ppbar avec le détecteur LHCb, en utilisant une luminosité intégrée de 0,7 fb⁻¹ accumulé à 7 TeV l'énergie de centre de masse en 2011, et une luminosité intégrée de 2 fb⁻¹ accumulé à 8 TeV l'énergie de centre de masse en 2012 les mesures sont effectuées en utilisant le J / ψ → ppbar décroissance comme un canal de référence. Haut de centre de masse des énergies disponibles dans les collisions proton-proton au LHC permet modèles décrivant la production de charmonium à tester. Nous distinguons rapidement présenté charmonia de ceux provenant de b-hadron se désintègre. Rapidement produites charmonia comprennent charmonia produit directement dans les interactions parton et ceux provenant de la désintégration de lourdes Etats quarkonium, qui sont à leur tour produit dans les interactions de partons. Production de charmonium invite comprend la production directe de l'interaction de parton et charmonium provenant de désintégrations des etats les plus lourds. Le taux relatif de la production rapide de l'etats η c et J / ψ dans l'acceptation LHCb (gamme de rapidité 2,0 6,5 GeV/c est mesurée pour la première le temps d'être σ (η c) / σ (J / ψ) = 1,74 ± 0,29 ± 0,28 stat syst ± 0,18 B l'énergie de centre de masse 7 TeV, et σ (η c) / σ (J / ψ) = 1,60 ± 0,29 stat ± 0,25 ± 0,17 syst B l'énergie de centre de masse 8 TeV. Utilisation du J / ψ section efficace de production mesurée par LHCb et en supposant qu'aucun J / ψ polarisation, l'absolu η c section efficace de production dans le même régime cinématique est σ η c = 0,52 ± 0,09 ± 0,08 stat syst ± 0,06 σ J / ψ, B l'énergie de centre de masse 7 TeV, et σ η c = 0,59 ± 0,11 stat ± 0,09 ± 0,08 syst σ J / ψ, B l'énergie de centre de masse 8 TeV. La troisième composante d'erreur correspond à l'incertitude de la J / ψ → p et η c → p ramification fractions et la mesure de section eficase J/ψ. Le rapport η c à J/ψ compris fraction de branchement de b-hadron désintégrations est mesuré pour être B (b → η c X) / B (b → J / ψ X) = 0,42 ± 0,06 ± 0,02 stat syst ± 0,05 B. Utilisation de l'J/ψ compris fraction ramification de b-hadron désintégrations mesuré avec le J/ψ →μμ canal de désintégration, l'inclusion η c ramification fraction de b-hadron désintégrations se trouve être B (b → η c X) = (4,9 ± 0,6 ± 0,3 stat syst ± 0,7 B) × 10 ⁻³, où la troisième composante d'erreur correspond à l'incertitude dans les J/ψ → pp et η c → pp ramification fractions (et le J/ψ compris fraction J ramification de b-hadron décroît). La mesure de la fraction η c de branchement inclus rapport de b-hadron se désintègre est la plus précise à ce jour. Utilisation de l'échantillon à faible fond de η c de b-hadron se désintègre, la différence de masse J / ψ et η c, ΔMJ / ψ, η c = 114,7 ± 1,5 ± 0,1 MeV / c², est mesurée. La valeur de la production par rapport compris η c J/ψ est important de faire la distinction entre une grande variété de modèles théoriques. Le η c section est mesurée dans des bacs de dynamique transversale. Il présente un comportement similaire à ceux obtenus dans l'analyse de la production J/ψ, mais avec beaucoup plus importantes incertitudes. Les limites supérieures sur la production de certains autres états charmonium sont adresséesThis thesis addresses a study of the η c (1S) charmonium state using decays to proton-antiproton final state at the LHCb experiment. The production cross-section of the η c meson in parton interactions and in b-hadron decays are reported. Production of the η c (1S) state is measured via the decay to ppbar with the LHCb detector, using an integrated luminosity of 0.7 fb⁻¹ accumulated at 7 TeV centre-of-mass energy in 2011, and an integrated luminosity of 2 fb⁻¹ accumulated at 8 TeV centre-of-mass energy in 2012. The measurements are performed using the J/ψ → ppbar decay as a reference channel. High centre-of-mass energies available in proton-proton collisions at the LHC allow models describing charmonium production to be tested. We distinguish promptly produced charmonia from those originating from b-hadron decays. Promptly produced charmonia include charmonia directly produced in parton interactions and those originating from the decays of heavier quarkonium states, which are in turn produced in parton interactions. Prompt charmonium production comprises direct production in the parton interaction and charmonium originating from decays of heavier states. The relative rate of prompt production of the η c and J/ψ states in the LHCb acceptance (rapidity range 2.0 < y < 4.5) and for p T (J/ψ , η c ) > 6.5 GeV/c is measured for the first time to be σ (η c) /σ (J/ψ) = 1.74 ± 0.29 stat ± 0.28 syst ± 0.18 B at a centre-of-mass energy 7 TeV, and σ (η c) /σ (J/ψ) = 1.60 ± 0.29 stat ± 0.25 syst ± 0.17 B at a centre-of-mass energy s = 8 TeV. Using the J/ψ production cross-section measured by LHCb and assuming no J/ψ polarization, the absolute η c prompt production cross-section in the same kinematic regime is found to be σ η c = 0.52 ± 0.09 stat ± 0.08 syst ± 0.06 σ J/ψ , B at a centre-of-mass energy 7 TeV, and σ η c = 0.59 ± 0.11 stat ± 0.09 syst ± 0.08 σ J/ψ , B at a centre-of-mass energy s = 8 TeV. The third error component corresponds to the uncertainty in the J/ψ → pp and η c → pp branching fractions and the J/ψ cross-section measurement. The relative η c to J/ψ inclusive branching fraction from b-hadron decays is measured to be B(b→η c X) /B(b→J/ψ X) = 0.42 ± 0.06 stat ± 0.02 syst ± 0.05 B. Using the J/ψ inclusive branching fraction from b-hadron decays measured with the J/ψ → μμ decay channel, the inclusive η c branching fraction from b-hadron decays is found to be B(b→η c X) = (4.9 ± 0.6 stat ± 0.3 syst ± 0.7 B) × 10 ⁻³ ,where the third error component corresponds to the uncertainty in the J/ψ → pp and η c → pp branching fractions (and the J/ψ inclusive branching fraction from b-hadron decays). The measurement of the relative η c inclusive branching fraction from b-hadron decays is the most precise to date. Using low-background sample of η c from b-hadron decays, the J/ψ and η c mass difference, ∆M J/ψ , η c = 114.7 ± 1.5 ± 0.1 MeV/c² , is measured. The value of the relative inclusive η c production to J/ψ is important for distinguishing between a variety of theoretical models. The η c cross-section is measured in bins of transverse momentum. It exhibits a similar behaviour to those obtained in the J/ψ production analysis, though with significantly larger uncertainties. The upper limits on the production of some other charmonium states are addressed
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Warren, Glen Andrew. "Induced final state proton polarization in neutral pion electroproduction near the [delta](1232) resonance at Q² = -0.126 GeV²/c²." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43306.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 1997.On t.p. "[delta]" appears as the lower case Greek letter.
Includes bibliographical references (p. 210-[211]).
by Glen Andrew Warren.
Ph.D.
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Wanotayaroj, Chaowaroj. "Search for a Scalar Partner of the Top Quark in the Jets+ETMiss Final State with the ATLAS detector." Thesis, University of Oregon, 2017. http://hdl.handle.net/1794/22275.
Full textAbstract:
This dissertation presents searches for direct pair production of a scalar partner of the top quark in events with only jets and \acrlong{met} in proton--proton collisions recorded during LHC Run 1 and Run 2 with the ATLAS detector. In the supersymmetry scenario, the partner is called top squark or stop. The stop ($\stop$) is assumed to decay via $\stop \to t \ninoone$, $\stop\to b\chinoonepm \to b W^{\left(\ast\right)} \ninoone$, or $\stop\ra bW\ninoone$, where $\ninoone$ ($\chinoonepm$) denotes the lightest neutralino (chargino). Exclusion limits are reported in terms of the stop and neutralino masses.
The LHC Run 1 analysis uses an integrated luminosity of 20.1~{\ifb} at $\acrshort{sqrts}=8~\tev$ to exclude top squark masses in the range $270$--$645~\GeV$ for $\ninoone$ masses below $30~\GeV$, assuming a 100\% $\stop \to t \ninoone$ \gls{br}. For a \gls{br} of $50\%$ to either $\stop \to t \ninoone$ or $\stop\to b\chinoonepm$, and assuming $m_{\chinoonepm} = 2 m_{\ninoone}$, stop masses in the range $250$--$550~\GeV$ are excluded for $\ninoone$ masses below $60~\GeV$.
The LHC Run 2 analysis uses an integrated luminosity of 13.3~{\ifb} at $\acrshort{sqrts}=13~\tev$. Assuming a 100\% $\stop \to t \ninoone$ \gls{br}, stop masses in the range $310$--$820~\GeV$ are excluded for $\ninoone$ masses below $160~\GeV$. For $\mstop\sim m_t+\mLSP$ scenario, the search excludes stop masses between $23$--$380~\GeV$. Additionally, scenarios where stops are produced indirectly through gluino decay but have very low $p_T$ signature due to a very small $\Delta (\mstop, \mLSP)$, have been considered. The result is interpreted as an upper limit for the cross section in terms of the gluino and stop masses. This excludes all models considered which include $m_{\gluino}$ up to 1600~\GeV\ with $\mLSP<560~\GeV$ at 95\% CL.
Finally, the analysis strategy from the LHC Run 1 search is applied in the broader scope of supersymmetry called \gls{pmssm}. This dissertation presents a summary of the results that related to the stop search.